/* imudp.c
* This is the implementation of the UDP input module.
*
* NOTE: read comments in module-template.h to understand how this file
* works!
*
* File begun on 2007-12-21 by RGerhards (extracted from syslogd.c)
*
* Copyright 2007 Rainer Gerhards and Adiscon GmbH.
*
* This file is part of rsyslog.
*
* Rsyslog is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Rsyslog is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Rsyslog. If not, see .
*
* A copy of the GPL can be found in the file "COPYING" in this distribution.
*/
#include "config.h"
#include
#include
#include
#include
#include
#include
#include "rsyslog.h"
#include "syslogd.h"
#include "net.h"
#include "cfsysline.h"
#include "module-template.h"
#include "srUtils.h"
MODULE_TYPE_INPUT
/* defines */
/* Module static data */
DEF_IMOD_STATIC_DATA
static int *udpLstnSocks = NULL; /* Internet datagram sockets, first element is nbr of elements
* read-only after init(), but beware of restart! */
static uchar *pszBindAddr = NULL; /* IP to bind socket to */
static uchar *pRcvBuf = NULL; /* receive buffer (for a single packet). We use a global and alloc
* it so that we can check available memory in willRun() and request
* termination if we can not get it. -- rgerhards, 2007-12-27
*/
typedef struct _instanceData {
} instanceData;
/* config settings */
/* This function is called when a new listener shall be added. It takes
* the configured parameters, tries to bind the socket and, if that
* succeeds, adds it to the list of existing listen sockets.
* rgerhards, 2007-12-27
*/
static rsRetVal addListner(void __attribute__((unused)) *pVal, uchar *pNewVal)
{
DEFiRet;
uchar *bindAddr;
int *newSocks;
int *tmpSocks;
int iSrc, iDst;
/* check which address to bind to. We could do this more compact, but have not
* done so in order to make the code more readable. -- rgerhards, 2007-12-27
*/
if(pszBindAddr == NULL)
bindAddr = NULL;
else if(pszBindAddr[0] == '*' && pszBindAddr[1] == '\0')
bindAddr = NULL;
else
bindAddr = pszBindAddr;
dbgprintf("Trying to open syslog UDP ports at %s:%s.\n",
(bindAddr == NULL) ? (uchar*)"*" : bindAddr, pNewVal);
newSocks = create_udp_socket(bindAddr, (pNewVal == NULL || *pNewVal == '\0') ? (uchar*) "514" : pNewVal, 1);
if(newSocks != NULL) {
/* we now need to add the new sockets to the existing set */
if(udpLstnSocks == NULL) {
/* esay, we can just replace it */
udpLstnSocks = newSocks;
} else {
/* we need to add them */
if((tmpSocks = malloc(sizeof(int) * 1 + newSocks[0] + udpLstnSocks[0])) == NULL) {
dbgprintf("out of memory trying to allocate udp listen socket array\n");
/* in this case, we discard the new sockets but continue with what we
* already have
*/
free(newSocks);
ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);
} else {
/* ready to copy */
iDst = 1;
for(iSrc = 1 ; iSrc <= udpLstnSocks[0] ; ++iSrc)
tmpSocks[iDst++] = udpLstnSocks[iSrc];
for(iSrc = 1 ; iSrc <= newSocks[0] ; ++iSrc)
tmpSocks[iDst++] = newSocks[iSrc];
tmpSocks[0] = udpLstnSocks[0] + newSocks[0];
free(newSocks);
free(udpLstnSocks);
udpLstnSocks = tmpSocks;
}
}
}
finalize_it:
free(pNewVal); /* in any case, this is no longer needed */
RETiRet;
}
/* This function is called to gather input.
*/
BEGINrunInput
int maxfds;
int nfds;
int i;
fd_set readfds;
struct sockaddr_storage frominet;
socklen_t socklen;
uchar fromHost[NI_MAXHOST];
uchar fromHostFQDN[NI_MAXHOST];
ssize_t l;
CODESTARTrunInput
/* this is an endless loop - it is terminated when the thread is
* signalled to do so. This, however, is handled by the framework,
* right into the sleep below.
*/
while(1) {
/* Add the Unix Domain Sockets to the list of read
* descriptors.
* rgerhards 2005-08-01: we must now check if there are
* any local sockets to listen to at all. If the -o option
* is given without -a, we do not need to listen at all..
*/
maxfds = 0;
FD_ZERO (&readfds);
/* Add the UDP listen sockets to the list of read descriptors.
*/
if(udpLstnSocks != NULL) {
for (i = 0; i < *udpLstnSocks; i++) {
if (udpLstnSocks[i+1] != -1) {
if(Debug)
debugListenInfo(udpLstnSocks[i+1], "UDP");
FD_SET(udpLstnSocks[i+1], &readfds);
if(udpLstnSocks[i+1]>maxfds) maxfds=udpLstnSocks[i+1];
}
}
}
if(Debug) {
dbgprintf("--------imUDP calling select, active file descriptors (max %d): ", maxfds);
for (nfds = 0; nfds <= maxfds; ++nfds)
if ( FD_ISSET(nfds, &readfds) )
dbgprintf("%d ", nfds);
dbgprintf("\n");
}
/* wait for io to become ready */
nfds = select(maxfds+1, (fd_set *) &readfds, NULL, NULL, NULL);
if(udpLstnSocks != NULL) {
for (i = 0; nfds && i < *udpLstnSocks; i++) {
if (FD_ISSET(udpLstnSocks[i+1], &readfds)) {
socklen = sizeof(frominet);
l = recvfrom(udpLstnSocks[i+1], (char*) pRcvBuf, MAXLINE - 1, 0,
(struct sockaddr *)&frominet, &socklen);
if (l > 0) {
if(cvthname(&frominet, fromHost, fromHostFQDN) == RS_RET_OK) {
dbgprintf("Message from inetd socket: #%d, host: %s\n",
udpLstnSocks[i+1], fromHost);
/* Here we check if a host is permitted to send us
* syslog messages. If it isn't, we do not further
* process the message but log a warning (if we are
* configured to do this).
* rgerhards, 2005-09-26
*/
if(isAllowedSender(pAllowedSenders_UDP,
(struct sockaddr *)&frominet, (char*)fromHostFQDN)) {
parseAndSubmitMessage((char*)fromHost, (char*) pRcvBuf, l, MSG_PARSE_HOSTNAME);
} else {
dbgprintf("%s is not an allowed sender\n", (char*)fromHostFQDN);
if(option_DisallowWarning) {
logerrorSz("UDP message from disallowed sender %s discarded",
(char*)fromHost);
}
}
}
} else if (l < 0 && errno != EINTR && errno != EAGAIN) {
char errStr[1024];
rs_strerror_r(errno, errStr, sizeof(errStr));
dbgprintf("INET socket error: %d = %s.\n", errno, errStr);
logerror("recvfrom inet");
/* should be harmless */
sleep(1);
}
--nfds; /* indicate we have processed one */
}
}
}
}
return iRet;
ENDrunInput
/* initialize and return if will run or not */
BEGINwillRun
CODESTARTwillRun
PrintAllowedSenders(1); /* UDP */
/* if we could not set up any listners, there is no point in running... */
if(udpLstnSocks == NULL)
ABORT_FINALIZE(RS_RET_NO_RUN);
if((pRcvBuf = malloc(MAXLINE * sizeof(char))) == NULL) {
ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);
}
finalize_it:
ENDwillRun
BEGINafterRun
CODESTARTafterRun
/* do cleanup here */
if (pAllowedSenders_UDP != NULL) {
clearAllowedSenders (pAllowedSenders_UDP);
pAllowedSenders_UDP = NULL;
}
if(udpLstnSocks != NULL)
closeUDPListenSockets(udpLstnSocks);
if(pRcvBuf != NULL)
free(pRcvBuf);
ENDafterRun
BEGINfreeInstance
CODESTARTfreeInstance
ENDfreeInstance
BEGINdbgPrintInstInfo
CODESTARTdbgPrintInstInfo
ENDdbgPrintInstInfo
BEGINmodExit
CODESTARTmodExit
ENDmodExit
BEGINqueryEtryPt
CODESTARTqueryEtryPt
CODEqueryEtryPt_STD_IMOD_QUERIES
ENDqueryEtryPt
static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp, void __attribute__((unused)) *pVal)
{
if(pszBindAddr != NULL) {
free(pszBindAddr);
pszBindAddr = NULL;
}
if(udpLstnSocks != NULL) {
closeUDPListenSockets(udpLstnSocks);
udpLstnSocks = NULL;
}
return RS_RET_OK;
}
BEGINmodInit()
CODESTARTmodInit
*ipIFVersProvided = 1; /* so far, we only support the initial definition */
CODEmodInit_QueryRegCFSLineHdlr
/* register config file handlers */
CHKiRet(omsdRegCFSLineHdlr((uchar *)"udpserverrun", 0, eCmdHdlrGetWord,
addListner, NULL, STD_LOADABLE_MODULE_ID));
CHKiRet(omsdRegCFSLineHdlr((uchar *)"udpserveraddress", 0, eCmdHdlrGetWord,
NULL, &pszBindAddr, STD_LOADABLE_MODULE_ID));
CHKiRet(omsdRegCFSLineHdlr((uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler,
resetConfigVariables, NULL, STD_LOADABLE_MODULE_ID));
ENDmodInit
/*
* vi:set ai:
*/